US2569567A - Apparatus for separating dust from dust-laden air - Google Patents

Description

A. H. KORN Get. 2, 1951 APPARATUS FOR SEPARATING DUST FROM DUST-LADEN AIR Filed Sept. 4. 1948 2 She ets-Sheet 1 INVENTOR. /4Kr/1w? M kir /v LII!!! In? 1 Oct. 2, 195] KORN 2,569,567

APPARATUS FOR SE PARATING DUST FROM DUST-LADEN AIR Filed Sept. 4, 1948 I 2 Sheets-Sheet 2 Q JNVENTOR. 45171411? ofi/v v BY Patented Oct. 2, 1951 UNITED STAT APPARATUS FOR SEPARATING DUST FRQM DUST-LADEN Arthur H. Korn, New York, N. Y.

App icati n S ptemb r 4, 1 48, S r a No- 47 864 4 Claims. (Cl. 183-47) My present invention relates generally toseparation of materials, and has particular reference to an improved method and apparatus for separating solid. particles from a gas. 7

The invention is useful for a variety of well- .kncwn p poses, and iS IlOt restricted to any particular use. For exampleit may be employed in the transportationand delivery of finely powdered materials, in the recovery of fine P OI particles irom-exhaustsand other gas A streamspor in the removaloi dustparticles from a gas stream which is to be purified.

For thesakeof simplicity; reference may hereinafter be made to "air streams, or to idust iladen air. Itwill beunderstood, however, that in eachicase the term a-ir is to haveab-roader s gn fi an to in lude gase ne al an h term dust is intended to include within its significance any particles of solidmatter re ardless ofth rsi o co o t o e: pri pal je o h n nt nis to prov de a me h a d a paratus whic re mor ef e t e ac ompl shing he des re s aratiohuand iefiicient even fo h ha dl n ef re atively smallquantities pf air or dust. Asubordi- .nate objective is to provide a relatively simple and unusua ly c mpac aratus whic may be manufactured and maintained in eflicient operation t elat e small e ens It is mm kn w e e tha c nt i u a sepst to s aremo e efi ct e f rthelarse pa tic s than for the sma ler ones- .A c nve t ona yc e eoa o amay h com le y e e t to separate particles pf a size over 100 microns,

. but it less eiifiectiveforparticles .of smaller size,

and usually it isnotei fective. at all forparticles smaller than 2'5v microns. It is a particular object pf-the present inventionto provide an improved procedureand apparatus by means of which. a t l sma l as 1 mic or e e sm ler ma be rel abl s p r ted fro a ga w il a l an a p ec a e n age o pa tic es ha in a e of l m c on-ma als b ed y a tu db heai (s eamv an car e along with it. The present invention is predicated upon the provision of a means for mini- .In z n this tu bulen e li iei ta ed the nrcs h impr v m t o cohsi ts n cau insthecost leee a r to r tat h n co fin pace f i ular cr ss-section. thereby causing the-solid particles therein to be thrown out .centritugally, withdrawing the dustfree air in an axial direction, and so controlling the flow of the air that during its movement toward the region of withdrawal it is separated into a plurality of substantially unimpeded transverse streams .in which a noneturbulent laminar flow is inducedto take place.

e resent improved apparatus is. one which brlngs about this result inawholly practical and economically feasible manner,

I achieve the e ge e l object and advanta es. and such other objects. and ad a 5 ,111.35? e einaftera ea or be poin d out, in t e m ner illustrativelyexemplified in the accompanys r w n s, in which:

Fig. 1 is an exterior elevational view of a typical separator constructed in accordance with the present invention andshown in association wit a typica hopper o rece vi g the s p e .Solid art cl Fi 2 an enla ed ele e on I S- C through the essential parts of the separator of Fig. 1;

Fig. 3 is a cross-sectional view taken substantially along the line 3-3 of Fig, 2;

Fig. 51 is a fragmentary perspective view showing the natureotthespaced annular discs forming part of the rotor;

Fig. 5 is a view similar to Fig. 2, illustrating the upper part of a separator of modified construction;

Fig. 6 is a crossesectional view taken substantia y alo g th l ne 6-6 of F g d Fig. 7 is a cross-sectional view taken substantially along the line 1-4 of Fig. 6.

Referring to Fig.1, the separator therein illust a cd by wa o e amp h s a e a a n amber A of circular cross-section and of cylindrical shape. This chamber is arranged with its axis vertical. At the ,bottom it is provided with an attachment flange ID by means of which it may be secured to a hopper or equivalent receptacle B, the attachment being effected by bolts H or the like- At the 1 91 end of the cylinder A there is a simi a attachm nt an e by means of which the cylinder is connected by bolts [3 or the like, to an extension A. This extension has an opening it! in its bottom wall, Whichis'coaxially arranged with respect to the chamber A. It also hasa iateral opening 15 to which any suitable conduit or pipe maybe connected.

The op ning !5 i an ut for t e r st am discs 32. I relationship to one an, ther and to the supporting the tangential inlet l6.

In the lower end of the chamber A there is a supporting spider I8 within which the lower end of a rotor shaft [9 is suitably journaled, as shown. The shaft 9 extends axially through the chamber A and its upper end is suitably connected as at with the shaft of a driving motor 2|. The

upper end of the shaft l9 isalso suitably journaled as at 22 in the upper part of the chamber portion A, as shown. In the latter journal assembly, there is included an oil seal 23, of well-known construction per se, which serves not only to prevent lubricating material to escape downwardly into the air stream, but also to prevent air from leaking upwardly through the journal part 22.

Near the lower end of the shaft l9, it is secured I by means of a pin 28 to a plate 29. Mounted upon the shaft l9, at the upper end of the chamber A, is an annulus 24. The support of this annulus is preferably achieved by means of a series of radial arms which connect with a hub 26. Extending between the plate 29 and the flange .part 3|] of the annulus 24 are a series of circumferentially spaced posts or tie rods 3|. I

have illustratively shown three such posts arranged at 120 intervals. They are screw- .threaded or otherwise secured at their opposite ends, respectively, to the flange 30 and to the plate 29. These posts pass through and support in spaced stacked relation a plurality of annular The shapes of these discs, and their posts 3| and the sha t l9, are best depicted in Fig. 4. Spacer elements 33 may be mounted upon vthe posts 3| between each pair of discs 32 in order to maintain these discs in predetermined spaced relationship.

The posts or tie rods 3|, and the spacers 33, are designed to have cross-sectional dimensions which are as small as possible.

The uppermost disc is as close to the flange so as it is to the adjacent disc below it. Similarly, .the endmost disc at the bottom is as close to the plate 29 as to the adjacent disc above it. The shaft I9 and the parts carried by it, viz., the annulus 24, the plate 29, and the stack of annular discs 32, constitute a rotor which is rubbing contact by means of a resilient backing ring 35, preferably composed of sponge rubber or the like. The ring bears upwardly against a downwardly-directed shoulder formed in the part A.

In operation, dust-laden air is introduced into The movement of the air into and through the separator is accomplished by establishing a suitable pressure differential between the inlet and the outlet. The entering air stream embarks upon a rotative movement as a result of the circular cross-section of the chamber into which it enters. The speed of this rotation will depend upon the pressure differential which is established between the inlet and the outlet, also upon the characteristics of the internal contour of the inlet It. In order to establish varying inlet velocities, an insert 36 is removably supported within the inlet IS. The contour of this insert (note the curvature of the surface 31 in Fig. 3) is of nozzledeflni ng character, and imparts a corresponding character and velocity to the entering air stream.

During the rotative movement of the air stream within the chamber A, the dust particles in the air are thrown out centrifugally, and fall by gravity toward the bottom of the chamber A, thence into the hopper or receptacle B. In order for the air to travel to the outlet l5, it is necessary for it to pass inwardly through the spaces between the discs 32. It is constrained to do this because the inlet opening l6 communicates only with the space on the outside of the rotor, while the outlet |5 communicates only with the space on the inside of the rotor, and the air seal afforded by the ring 34 rubbing against the annulus 24 prevents any by-passing of the air stream from the inlet to the outlet. Also, the proximity of the plate 29 to the endmost disc 32 prevents the air stream from traveling around the lower end of the rotor into the inside of the rotor.

The motor 2| is so chosen or regulated that the peripheral velocity of the discs 32 is substantially the same as, or slightly greater than, the speed of the rotating air stream. This helps to keep the air in a state of rotation for a protracted period, and any drag of the disc peripheries upon the air is one which accelerates the rotation and thus enhances the centrifugal dust-separating action. Of primary importance is the fact that the air is subdivided into a plurality of superposed transverse streams during its travel from the wall portion of the chamber A to the axial region of this charber. These transverse streams are impeded to a minimum extent (only by the spacers 33) and are of such narrow and flattened character as to induce a laminar flow. In this way, the turbulence which normally impairs the efficiency of a centrifugal separator is almost completely eliminated, and at least minimized to a highly desirable degree.

The spacing of the discs 32 will depend upon the radial velocity of the air through the spaces between them. This, in turn, is determined by the pressure differential with which the apparatus is used, the length of the rotor, and the outside diameter of the discs themselves. If the discs are spaced too far apart, the desired laminar flow will not be induced. If the discs are spaced too closely together, they will obstruct the passage of air. A suitable spacing in a separator passing 1 cubic foot of air per second, with a rotor 1 foot long, having an outside diameter of about 4 inches, and rotating at about 3400 R. P. M., is of an inch. It will be understood, however, that these figures are purely illustrative, and that the invention is not restricted to any particular size of the parts or capacity of the apparatus as a whole.

In the modified construction shown in Figs.

greater upon a rotor shaft 39. 'Inth-is case, however, the

S .iz-pper endoof L the rotor "shaft is journaled as at bymountin-ga turbinewheelupon thisshaft in the region of the entering air;

' This turbine is designated by the referencenumeral'jband is shaped'toconstitute "an annulus supported-"by 7 radial arms 63.,upontheshaft flfl.. This annulus, as before, is provided with ,a.,flanged part s-to which the longitudinal posts ,..4'.5, ar.e secured, .these posts passing through and supporting "the discs 38. Also as before, the upper surface of the annulus 42 is maintained in rubbing contact with a sealing ring 46 by means of a resilient sponge rubber ring 41.

Formed on the periphery of the annulus 42 are vanes 48 which extend. toward but terminate short of the wall of the chamber 49, as shown most clearly in Fig. 6. These vanes are arranged in the path of the entering air stream, and this air stream is controlled by the contour of the removable insert 56. It will be noted that this contour is such that the insert serves not only as a nozzle-defining instrument, but also as a deflector to direct theincoming air stream toward the space beyond the vanes 38. This deflection prevents the solid dust particles in the entering air stream from impinging upon the vanes -58 and thus protects the vanes against undue wear or abrasion. Also, since the dust particles may be traveling at a speed slower than that of the air stream, a deflection of these particles away from the vanes prevents impairment of the propelling effect of the air against these vanes.

In view of the fact that the tangential inlet opening (corresponding to the inlet [6 of Fig. 3) is slightly tapered inwardly, as shown, the insert 50 may be held in position by simply contouring its outer surfaces in similar fashion. Once placed in position, it cannot shift inwardly because of the taper referred to; and it cannot slip rearwardly after suitable connection has been established at the connectin flange 52.

The device illustrated in Figs. 5 and 6 functions substantially the same as that previously described.

In each of the embodiments illustrated, to prevent undue abrasion, that part of the Wall of the separating chamber against which the entering air stream impinges, may be constructed in replaceable fashion, as is well-known.

As an indication of the unique advantages achieved by the present invention, an installa-- tion of the character hereinbefore illustratively mentioned (having a rotor 1 foot long, an outside diameter of 4 inches, a disc spacing of 1%; of an inch, a speed of rotation of 3400 R. P. M., and a capacity of 1 cubic foot per second) efficiently separates virtually 100 per cent of all particles of dust having a size greater than microns, and separates correspondingly smaller percentages of particles of even smaller sizes.

By rotating the air faster, or by making the rotor larger in diameter, or both, a greater centrifugal action may be achieved, as a result of which an even finer separation of dust particles can be accomplished. A similar result is capable of accomplishment by cutting down on the volume of air which passes through the apparatus in a given interval of time.

The ability to separate dust down to a particle size approaching 1 micron is an advantage which 'will be readily-appreciated by those skilled in the industrial arts. 'Theapplicability 'of the present invention topigments and colloidal'grap'hites will 'be apparent.

The invention-is also useful the-recovery of "fine powders from air streams and othergases. For example, it may be-used in the-recovery of 'valuable metallic vapor condensations "from furnace gases.

"The invention is particularly suited for use in the picking up; transportation, and delivery of finely powdered dry materials in various produc- "tionoperations.

For example; in any production process in which powdered -or granular material isto be moved from-place to place (from mixer to mill, from mill to sif-ter, from-any item 7 of manufacturing equipment to filling machine, etc;) the present'procedure and invention are unusually efiicient and useful.

The applicability of the invention to the charging and periodic replenishing of feed hoppers, for packaging machines, molding machines, tablet presses, and the like, is obvious.

In general, it will be understood that the details herein described and illustrated are in many respects of purely illustrative character, to explain the nature, purpose and mode of operation of the process and apparatus. Many of these details may obviously be modified by those skilled in the art without necessarily departing from the spirit and scope of the invention as expressed in the appended claims.

Having thus described my invention and illustrated its use, what I claim as new and desire to secure by Letters Patent is:

1. In a separator of the character described, an axially-vertical chamber of circular cross-section, a rotor coaxially mounted within said chamher and comprising a stack of spaced annular discs concentric with the rotor axis, a tangential inlet for dust-laden air communicating with the space on the outside of said rotor, an air outlet communicating with the space on the inside of said rotor, means constraining the air passing through said chamber to travel inwardly through the spaces between said discs, and means for rotating said rotor in the direction of air movement to accelerate the rotative component of said movement and induce a laminar non-turbulent air flow through said spaces, said means comprising a turbine wheel carried by the rotor and positioned in the region of the entering air for propulsion thereby.

2. In a separator of the character described, a chamber of circular cross-section, a rotor 00- axially mounted therein and comprising a stack of spaced annular discs concentric with the rotor axis, a tangential inlet for dust-laden air communicating with the space on the outside of said rotor, an air outlet communicating with the space on the inside of said rotor, and means for rotating said rotor in the direction of air movement, said means comprising a turbine wheel carried by the rotor and positioned in the region of the entering air for propulsion thereby, said turbine wheel being provided on its periphery with vanes extending toward but terminating short of the wall of said chamber, and a deflector in said air inlet for guiding the entering air stream toward the annular space beyond said vanes, said deflector having a contour which produces a propulsion jet.

3. A separator constructed as set forth in claim 2 wherein said deflector comprises an insert removably supported Within said air inlet and pro- 7 vided with a nozzle-defining contour which controls the velocity of the entering air stream.

4. In a separator of the character described, a tubular chamber, a shaft mounted axially within the chamber and. rotatably supporting a stack of axially spaced members transverse to said shaft which form an axial passage adjacent the shaft, an inlet for dust-laden air communicating with the space outside of said members, an air outlet communicating with said passage, means constraining the air passing through said chamber to travel inwardly through the spaces between said members and means for rotating said shaft and members in the direction of air movement, said last named means comprising a turbine wheel carried by the shaft and positioned in the region of the entering air for propulsion thereby.

ARTHUR H. KORN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 262,183 Hogan Aug. 1, 1882 1,505,564 Jett Aug. 19, 1924 2,119,478 Whiton May 31, 1938 2,126,481 Lapp et a1 Aug. 9, 1938 FOREIGN PATENTS Number Country Date 620,108 France Jan. 12, 1927

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